Cavendish Laboratory is aPhysics Laboratory。The entrance to the former site of Cavendish Laboratory is actually its physics department.University of CambridgeBuilt in 1209, it has a long historyOxfordIt is also the highest school in Britain.The Cavendish Laboratory of Cambridge University was built between 1873 and 1874 with the private donation of William Cavendish, a president of Cambridge University at that time.He was a scientist who made great contributions to physics and chemistry in the 18th and 19th centuriesHenry Cavendish A close relative of.The laboratory was named Cavendish Laboratory. At that time, a donation of 8450 pounds was spent to build an experimental building and buy some instruments and equipment.
Cavendish Laboratory isUniversity of CambridgeDepartment of Physics, byelectromagneticsFatherJames Clerk Maxwell It was founded in 1871 and the laboratory was built in 1874.In memory of the greatphysical scientist, Chemist, Cambridge University AlumniHenry Cavendish And named Cavendish Laboratory.William Cavendish (7th generation), then President of Cambridge UniversityDuke of Devon）He is a relative of Henry Cavendish. He donated 8450 pounds to help prepare the laboratory.Maxwell was then employed as the first Cavendish professor of physics (laboratory director) at Cambridge University.Because of Maxwell's lofty position and the glorious history of Cavendish Laboratory, Professor Cavendish of Physics has become an honorary title that is respected and passed down from generation to generation like Lucas Professor of Mathematics, and has been passed down to the ninth generation.The research fields of the laboratory includeAstrophysics、Particle physics, solid state physicsBiophysics。Cavendish Laboratory is the first socialized and specialized scientific laboratory in the history of modern science, which has given birth to a large number of important enough to affect human progressScientific achievements, including the discovery of electrons, neutronsNucleusStructure and discovery ofDouble helix of DNAStructure and x-ray scattering have made significant contributions to the development of human science.
Britain was the most developed country in the 19th centurycapitalist countryone of.holdPhysics LaboratoryIt was expanded from the private residence of scientists to become a research unit, which conformed to the second half of the 19th centuryIndustrial technologyThe requirements for scientific development have played a very good role in scientific researchFacilitation。With the development of science and technology, the scale of scientific research is becoming larger and larger, and socialization and specialization are inevitable trends.The history of Cavendish Laboratory in the following decades proves thatUniversity of CambridgeThe headmaster is far sighted.
Historical development
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Created by: Maxwell
The famous physicistElectromagnetic field theoryFounder ofJames Clerk Maxwell 。He also served as the first Cavendish professor of physics, actually the director of the laboratory or the director of the physics department, until he died of illness in 1879 (only 48 years old).Under his auspices, Cavendish Lab carried out teaching and a number ofscientific researchAccording to Maxwell's idea, we should systematically teach physics, and at the same time, we should also perform experiments.The performance experiment requires simple structure and easy for students to master.He said, "These experimentseducational value It is often inversely proportional to the complexity of the instrument. Although students often have problems with self-made instruments, they will learn more than carefully adjusted instruments.The carefully adjusted instrument is easy for students to rely on and dare not disassemble into parts. "Since then, the use of self-made instruments has formed the tradition of Cavendish Laboratories.
The laboratory is attached with a factory, which can make very precise instruments,James Clerk Maxwell Very seriousscientific methodTraining, especiallyHistory of ScienceResearch.For example, he spent several years sorting out H. Cavendish's works on electrical experiments a hundred years ago, and led us to repeat and improve some of the experiments that Cavendish had done.Some people didn't understand his idea, but it turned out that Maxwell was far sighted.At the same time, Cavendish Laboratory has also conducted a number of studies, such as: geomagnetismelectromagnetic waveSpeed, electrical constantprecision measurement 、Ohm's lawExperiments, spectral experimentsBiaxial crystalThese works have played a role in opening up the way for future generations.
James Clerk Maxwell 's successor isJohn William Strutt 。He is accomplished in acoustics and electricity.Under his auspices, Cavendish Lab systematically set up student experiments.In 1884,John William Strutt He resigned because he was elected professor of the Royal CollegeJ.ThomsonSuccession.
Third term: JJ. Thomson
J. J. Thomson (i.eJoseph John Thomson ）He has made outstanding contributions to Cavendish Laboratory. Under his advice, since 1895, Cavendish Laboratory has implemented the system of recruiting graduates from foreign schools (including foreign ones) as graduate students. Lots of outstanding young people have come here in successionStudy and research under the guidance of J Thomson.During his 35 years in office, the staff of Cavendish Laboratory carried out the following work:Gas conductionThe research of the, which led to the discovery of the electrons;Carried outPositive rayAnd inventedMass spectrometer, resulting inisotopeResearch;yeselementary chargeCarry out measurement and continuously improve the method, laying the foundation for the future oil flowing experiment;expandCloud chamberInvention ofElementary particleOur research provides a powerful weapon;Electromagnetic wave andThermionicOur research led to a vacuumdiodeAnd the invention of triodeRadio ElectronicsDevelopment and application of.Others such asX-ray，radioactivityAnd αBeta rayOur research is in the leading position in the world.
It should be pointed out that the Cavendish Laboratory has made so many contributions to the development of modern physics because of its specific era background and social conditions, but the experience it has created is still worth learning.
Nobel Prize Winner
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Cavendish Laboratories asUniversity of CambridgeA department of the Academy of Physical Sciences produced 29 students in the 85 years from 1904 to 1989Nobel PrizeWinners account for one third of the total number of Nobel Prizes awarded by Cambridge University.If it is regarded as a university, its number of winners can be ranked 20th in the world, andStanford UniversitySide by side.Its scientific research efficiency is amazing, and its achievements are unparalleled in the world.In its heyday, it was even praised as "one half of the world's physical discoveries came from Cavendish Laboratories."
Winners and main achievements:
John William Strutt The third generation Baron Rayleigh (physics, 1904) studied the gas density and found argon
Measured by British physicist Cavendish in 1789Gravitational constantPhysical instrument invented by
principle
The double amplification method is used
1. The length of the T-frame connecting the two balls is increased as much as possible, so thatUniversal gravitationProduce greater torque to deflect the rod
2. Try to increase the distance between the arc ruler and the system so that thereflected lightRotate a large angle on the arc
Gravitational constant G=6.67 * 10 ^ (- 11)
Demonstrating Cavendish torsion scale experiment
In 1789, the British physicist H. Cavendish successfully measured the value of the gravitational constant using a torsion balance, proving thatLaw of universal gravitationIs correct.Cavendish's idea to solve the problem is to convert the small change that is difficult to observe into the significant change that is easy to observe, and then calculate the small change according to the relationship between the significant change and the small change
Cavendish uses a large iron ball and a small iron ball to placeTorsion scaleBoth ends of.In the middle of the torsion scale, a steel wire with good toughness is tied to the bracket, and there is a small mirror on the steel wire.usecollimationWhen a thin beam of light shines on the mirror, the light will be reflected to a far placelight spotLocation of.
Use two iron balls with the same mass to attract two iron balls on the torsion scale at the same time.becauseUniversal gravitationAs a result, the torsion balance slightly deflects, but the reflection point formed by the beam in the distance moves a large distance.He used this to calculateUniversal gravitation formulaThe constant G in.
The ingenuity of this experiment lies in the amplification of the weak force, especiallyReflection of lightUtilization of.
